African Swine Fever (ASF) Response

Ready Reference Guide—

ASF Zones and Areas for Domestic Swine

July 2020 USDA APHIS Veterinary Services • Na�onal Preparedness and Incident Coordina�on (NPIC) 1 of 3

4700 River Road Unit 41 • Riverdale, MD 20737

 Zones and Areas Domestic Swine Premises

 

Note: Stamping-out is not pictured in these figures. The Surveillance Zone is part of the Free Area.

Summary of ASF Zone and Area Designations

Zone/Area Definition

Infected Zone (IZ) Zone that immediately surrounds an Infected Premises or Infected Pig(s)

Buffer Zone (BZ) Zone that immediately surrounds an Infected Zone or a Contact Premises

Control Area (CA) Consists of an Infected Zone and a Buffer Zone

Surveillance Zone (SZ) Zone outside and along the border of a Control Area. The Surveillance Zone is part of the 

Free Area.

Free Area (FA) Area not included in any Control Area. Includes the Surveillance Zone.

Summary of Key Response Actions

Swine Population 

Infected

State – Tribal Quarantine 

of Infected Premises

Control Area Plus 

Network Based Controls

USDA Extraordinary 

Emergency Declaration

72 hour National 

Movement Standstill

Domestic Swine 

Only

Yes Control Area 

+

Network Based Controls

Yes Yes

Zone, Areas, and Premises Designations

Minimum Size of Zones and Areas
African Swine Fever (ASF) Response

Ready Reference Guide—

ASF Zones and Areas for Domestic Swine

July 2020 USDA APHIS Veterinary Services • Na�onal Preparedness and Incident Coordina�on (NPIC) 2 of 3

4700 River Road Unit 41 • Riverdale, MD 20737

 Summary of ASF Premises Designations 

Recommended Sampling Scheme for an ASF outbreak response

 Factors to Consider in Determining Control Area Size for ASF

1Premises designa�on: Infected Premises (IP), Contact Premises (CP), At-Risk Premises (ARP), Monitored Premises (MP), Free Premises (FP). 2Frequency of sampling is subject to change and can be adjusted based on observed incuba�on periods, likely route of disease introduc�on, feasibility of sampling and disease introduc�on risk. 3If feral swine are present, more frequent sampling throughout the quaran�ne period is recommended.
African Swine Fever (ASF) Response

Ready Reference Guide—

ASF Zones and Areas for Domestic Swine

July 2020 USDA APHIS Veterinary Services • Na�onal Preparedness and Incident Coordina�on (NPIC) 3 of 3

4700 River Road Unit 41 • Riverdale, MD 20737

The first Infected Premises (IP1) identified an epidemiologically-linked Contact 

Premises outside of the initial Control Area. NBCs requiring testing were placed 

on that Contact Premises, which resulted in a positive detection. This additional 

Infected Premises (IP2) triggered a new Control Area that led to additional Contact Premises.

All premises that are traced/linked to an Infected Premises are subject to Control 

Area restrictions and diagnostic testing.

Zones and Network Based Control

IP1 First Infected Premises

IP2 Additional Infected Premises

For more information, please go to:

https://www.aphis.usda.gov/aphis/ourfocus/animalhealth/emergencymanagement/african-swine-fever/african-swine-fever

For more details on zones and premises designations, please see the APHIS FAD 

Framework: Response Strategies (Manual 2-0)

For the ASF Response Plan: The Red Book, click here